Shock resisting lamp receptacle



27, 1940- R. A. BLOOD 2,212,728

SHOdK RESISTING LAMP HECEPTACLE Filed March 31, 1939 2 Sheets-Sheet l i k INVENTORV ATTORNEYS.

Au 27, 1940. R; BL OD 2,212,723

SHOCK RESISTING LAMP RECEPTACLE Filed March 31, 1939 2 Sheets-Sheet 2 ATTORNEYS.

Patented Aug. 27, 1940 I TENT OFFICE 2,212,728 I SHOCK'RESISTING LAMP RECEPTACLE Robert A- Blood, I Syracuse, N. Y., assignor to Grouse-Hinds Company, Syracuse, N. Y., a corporation of New York Application March 31, 1939, Seriai No. 265,321

2 Claims.

This invention relates to shock resisting lamp receptacles and has as a generalobject an improvement of that type of device asshown in my copending application, Sr. No. 111,269, filed November' 17, 1936, which matured into Patent No. 2,174,773, onOctober 3, 1939.

More particularly the invention has as an object a shock resisting lamp receptacle embodying a Structure wherebythe screw shell is permitted to move axially relative to the body with the contacts for connecting the device to the supply wires being fixedly secured to the screw shell and its center terminal and serving as spring means to urge the screw shell in one direction and a separate spring means urging the screw shell in opposite direction against the springtension of the contacts.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all theviews.

Figure 1 is a vertical sectional view of a shock resisting lamp receptacle embodying my invention illustrating the receptacle mounted in a lighting unit. I

Figure 2 is a plan view of the open end of the receptacle.

Figure 3 is a plan viewof the top end of the receptacle.

Figure 4 is a plan view of the open end of the body of the receptacle with the screw shell removed.

Figure 5 is a vertical sectional view of the receptacle being on substantially lines 55, Figure 2. v v I I Figure 6 is a top plan view of the screw shell member.

Figure 7 is a sideelevational view of the thrust spring employed in the receptacle.

The receptacle comprises a body member ID formed or molded from suitable plastic material. The body is preferably provided with an externallythreaded portion I I to permit the receptacle to be screwed into the body I2 of a lighting fixture. The body It] is formed with a substantial recess, the outer portion of which is enlarged as at I3. The peripheral margin, about the enlargement I3 of the recess, is provided with a plurality of threaded apertures I4 to receive screws I5 employed to secure an annular member I6 to theopen end of the body and which extends inwardly and overlaps the enlargement I3 of the recess.

A pair of spring contacts ll, it are mounted in the bottom of the recess and are secured to the body at like ends by screws I3 which are here shown as threading into metallic inserts 2G, and to the outer end of.,which are secured terminals 2i provided with binding screws 22 to permit the receptacle to be wired to the supply lines. I

The screw shell member consists of a metallic shell 23, a disk .24 of insulating material, and a central terminal 25. The disk 24 is secured to the inner end of the screw shell by rivets 26. The terminal 25 extends from the center of the disk outwardly and is bent over the edge of the disk and extends inwardly across the top of the same, the free end being'secured to the disk by a rivet 21. The bight oi the terminal is arranged in a slot 28 and both legs of the terminal and the disk are provided with apertures 29. The screw shell 23 is provided with a tab portion 30 extending inwardly across the top of the disk 24 and provided with an aperture 3| arranged in register with a similar aperture in the disk.

The free end of the contact I1 is secured to the central terminal 25 by a screw 34 extending through the terminal and threading into aperture 35 in contact I1. Contact I8 is secured to a the tab 30 of the screw shell in a similar manner by screw 36. The contacts I'I, I8 are formed of spring material and tendto urge the screw shell member of the receptacle inwardly toward the bottom of the recess.

The screw shell 23 is formed with a radially extending flange 38 arranged in the enlargement I3 of the recess, and the screw shell is encircled by a thrust spring 39 having depending portions 40 engaging the flange 38, the annular portion of the spring 39 engaging the bottom of the enlargement I3. The spring 39 acts against the flange 38 to yieldingly urge the screw shell 23 outwardly against the tension of the spring contacts II, I8. In this manner, the screw shell is-provided with a floating mounting and is permitted an axial movement relative to the body I0. Axial movement of the screw shell 23 in both directions is limited by engagement of the flange 38 with the bottom of the enlargement I3 of the recess, or with the annular member I6. The body is provided with an axially extending slot 45 in the wall of the recess, and the screw shell with a projection 46 slidaloly mounted in the slot 45 and serves to prevent rotation of the screw shell relative to the body. 7

It will be observed that the contacts I7, I8 are fixedly connected to the screw shell and the cen- M tral terminal 25. Accordingly, there is a continuous metallic circuit from the feed wires to the screw shell and the central terminal 25 and which does not employ spring pressed. connections as is customary in devices of this type.

I have found. that the spring 39 acting in opposition to the spring contacts ll, l8, renders the receptacle more sensitive to vibrations of small magnitude such as those resulting from the operation of machinery in the building. At the same time, the screw shell is adequately supported and is maintained in normal position relative to the body whereby the lamp bulb does not become moved out of focus with the lighting unit in which the receptacle is mounted. I

What I claim is: v

1. A shock resisting lamp receptacle comprising a body formed with a recess, a screw shell mounted in said recess and having acentral terminal and being provided at its periphery with a radially extending flange, a pair of spring contacts mounted at the .bottom of said recess and -being secured at like ends to the body and at their opposite ends to said screw shell and central terminal respectively, said spring contacts yieldingly urging said screw shell inwardly toward the bottom of said recess, spring means encircling said screw shell and coacting with the body and the flange of the screw shell to yieldingly urge the latter outwardly against the tension of said spring contacts, and said flange coacting with the body to limit axial movement of said screw shell.

2. A shock resisting lamp receptacle comprising a body formed with a recess, said recess being enlarged at the open end thereof, a screw shell arranged in said recess and being provided with a central terminal and a radially extending flange arranged in the enlarged portion of said recess,

I a pair'of spring contacts mounted at the bottom of said recess and being secured at like ends to the body and at their opposite ends to said screw shell and central terminal respectively and being operable to yieldingly urge said screw shell inwardly toward the bottom of said recess, an annular member detachably secured to the open end of the body and overlying the enlarged portion of said recess, a' spring encircling said screw shell and arranged intermediate the bottom of the enlarged portion of said recess and the flange of said screw shell and being operable to yieldingly urge said screw shell outwardly against the tension of said spring contacts.

' ROBERT A. BLOOD. 

